设计模式之State(状态模式)浅析

这个是照着一篇文章实现的ruby版。文章链接
http://blog.csdn.net/shuangde800/article/details/10132825?reload

#encoding: utf-8
class State
  #封装四种动作
  def insertQuarter ;end #投币
  def ejectQuarter ;end  #退币 
  def turnCrank ;end     #转动摇柄
  def dispense ;end      #发糖果
end

#没有投币的状态
class NoQuarterState < State
  def initialize(gumballMachine)
      @gumballMachine = gumballMachine
  end
  
  def insertQuarter
    p "你插入一枚硬币"
    p @gumballMachine.setState(@gumballMachine.getHasQuarterState)
  end
  
  def ejectQuarter
    p "你没有插入任何硬币"
  end
  
  def turnCrank
    p "你转动手柄，但是没有硬币插入"
  end
  
  def dispense
    p "首先你需要付钱"
  end
  
  def toString()
    return "等待插入硬币"
  end
end

#已经投币的状态 
class HasQuarterState < State
  def initialize(gumballMachine)
      @gumballMachine = gumballMachine
  end
  
  def insertQuarter
    p "你不能在插入别的硬币"
  end
  
  def ejectQuarter
    p "硬币吐出"
    @gumballMachine.setState(@gumballMachine.getNoQuarterState);  
  end
  
  def turnCrank
    p "你转动手柄..."
    @gumballMachine.setState(@gumballMachine.getSoldState)
  end
  
  def dispense
    p "没有糖果发放"
  end
  
  def toString()
    return "等待转动手柄"
  end
end

#正在售出的状态
class SoldState < State
  def initialize(gumballMachine)
      @gumballMachine = gumballMachine
  end
  
  def insertQuarter
    p "请等待，将要给你糖果"
  end
  
  def ejectQuarter
    p "对不起，你已经转过手柄"
  end
  
  def turnCrank
    p "转动两次不会给你多余的糖果"
  end
  
  def dispense
    @gumballMachine.releaseBall
    if @gumballMachine.getCount>0
      @gumballMachine.setState(@gumballMachine.getNoQuarterState)
    else
      p "哦no，已经没有糖果了"  
      @gumballMachine.setState(@gumballMachine.getSoldOutState)
    end
  end
  
  def toString()
    return "等待转动手柄"
  end
end

#卖完状态
class SoldOutState < State
  def initialize(gumballMachine)
      @gumballMachine = gumballMachine
  end
  
  def insertQuarter
    p "请等待，将要给你糖果"
    p @gumballMachine
  end
  
  def ejectQuarter
    p "对不起，你已经转过手柄"
  end
  
  def turnCrank
    p "转动两次不会给你多余的糖果，或者糖果卖完了"
  end
  
  def dispense
    p "没有糖果发放"
  end
  
  def toString()
    return "等待转动手柄"
  end
end

class GumballMachine   
   def initialize(numberGumballs)
     @soldOutState = SoldOutState.new(self)
     @noQuarterState = NoQuarterState.new(self)
     @hasQuarterState = HasQuarterState.new(self)  
     @soldState = SoldState.new(self)
     @count = numberGumballs
     if numberGumballs > 0
       @state = @noQuarterState
     end
   end
   
   def insertQuarter
     @state.insertQuarter
   end
   
   def ejectQuarter
     @state.ejectQuarter
   end
   
   def turnCrank
     @state.turnCrank
     @state.dispense  
   end
   
   def setState(state)
     @state=state
   end
   
   def releaseBall
     p "糖果正在给你..."
     if @count!=0
       @count = @count - 1
     end
   end
   
   def getCount
     @count
   end
   
   def refill(count)
     @count = count
     @state = @noQuarterState
   end
   
   def getState
     @state
   end
   
   def getSoldOutState
     @soldOutState
   end
   
   def getNoQuarterState
     @noQuarterState
   end
   
   def getHasQuarterState
     @hasQuarterState
   end
   
   def getSoldState
     @soldState
   end
end

#测试
@test = GumballMachine.new(5)
@test.insertQuarter  
@test.turnCrank  
p @test  
@test.insertQuarter  
@test.turnCrank
@test.insertQuarter  
@test.turnCrank
p @test